Vehicle hauling trailers typically have two long vehicle ramps onto which the vehicles being hauled are driven and secured. Securing the vehicle on the ramp is extremely important to keep the vehicle from swaying and bouncing during transit.
The preferred method in the industry for securing the vehicle to the ramps is with heavy-gauge chain, and modern automobiles are equipped by the manufacturer with special receptacles in their frames to which such chains can be attached, usually by way of hooks. The other end of each chain is attached, by welding or with suitable fasteners, to a winch axle extending transversely across or under the ramp. One end of each winch axle extends from the side of the ramp, and is provided with a gear and pawl arrangement into which a handle or lever, for example, a tire iron, can be inserted to rotate the winch axle and tighten the chain hooked to the vehicle. There are usually four such winch axles and associated chains per vehicle. Examples of such tie-down systems are disclosed in U.S. Pat. No. 3,053,508 to Schultz, U.S. Pat. No. 3,566,804 to Mietla, U.S. Pat. No. 4,147,113 to Kilgus, and U.S Pat. No. 4,273,484 to Blanar.
Because a single trailer is typically used to haul a variety of vehicles having different sizes and configurations, the length of the chain becomes a critical factor. Chains must be long enough to secure the largest vehicle which might possibly be carried on the trailer. However, when shorter vehicles are loaded there remains a substantial excess length of chain which must be stored securely to prevent it from swinging around during loading and transit and damaging the vehicles on the trailer. With the heavy gauge chain used to secure the vehicles it frequently occurs that not all of the excess chain can be wound about the winch axle. Prior art solutions to this problem include providing the chain with a secondary hook to cinch up the extra length of chain, or providing a number of chains of different lengths. The first solution still leaves the cinched or excess portion of chain to hang and sway, especially during the loading procedure. The second method is not economical and requires an inordinate amount of time for changing each chain on each winch axle.
Another feature incorporated in older tie-down systems is a ladder-like structure extending laterally between ramps. Many vehicle manufacturers require that vehicles be tied down utilizing restraints disposed at a specified angle. The ladder provides a convenient structure for maintaining the proper angle with respect to the ramp at which the chain exerts tension on the vehicle to hold it motionless on the ramp. Each chain is threaded between the bars of the ladder to a point adjacent the hook-receiving frame receptacle, and then partially encircles one of the bars in the ladder upwardly toward the receptacle and hooked in place. A problem with prior ladder structure is that the over and under threading of the chain through the bars is inconvenient for the operator and creates the possibility of damage to the vehicles when the chain is dropped between the bars of the ladder, either accidently or for the purpose of threading it therethrough. Such prior art ladder structure is disclosed in U.S. Pat. No. 4,273,484 to Blanar.